Schedule of components of inventories (Details) - USD ($)	Mar. 31, 2022	Jun. 30, 2021
Inventory Disclosure [Abstract]
Parts inventory	$ 1,735,000	$ 1,779,000
Work in process	102,000	23,000
Finished goods	334,000	445,000
Estimated inventory to be returned	205,000	167,000
Less: Reserve for obsolescence	(287,000)	(300,000)
Total	$ 2,089,000	$ 2,114,000